Field of the Invention
The present invention relates to a system and method for measuring the insulation resistance of a fuel cell vehicle to prevent a driver from receiving an electrical shock, which may occur when the insulation resistance of a high-voltage battery and a fuel cell decreases to less than a certain level in a fuel cell vehicle that includes a high-voltage battery.
Description of the Related Art
A fuel cell system applied to a hydrogen fuel cell vehicle, which is a type of eco-friendly, next-generation vehicle, is configured to include a fuel cell that generates power from an electrochemical reaction of reactant gases, a hydrogen supply system that supplies hydrogen as fuel to the fuel cell, an air supply system that supplies gas, including oxygen as an oxidant necessary for electrochemical reactions, a heat and water management system that manages water and optimally adjusts the operating temperature of the fuel cell by emitting heat, which is a by-product of the electrochemical reactions therein, and a fuel cell system controller that operates the fuel cell system.
In a fuel cell vehicle in which such a fuel cell system is installed, when a fuel cell is used as the power source of the vehicle, all of the loads included in the vehicle depend on the fuel cell, thus degrading performance when the efficiency of the fuel cell is low. Additionally, when a sudden load is applied to the vehicle, since the output voltage of the fuel cell decreases rapidly, sufficient power cannot be supplied to a drive motor, thus decreasing the performance of the vehicle. Furthermore, since the fuel cell has unidirectional output, energy from the drive motor may not be recovered when the vehicle brakes, thus degrading the efficiency of the vehicle system.
Accordingly, a hybrid fuel-cell vehicle has been developed. The hybrid fuel-cell vehicle is a system in which a rechargeable battery, that is, a high-voltage battery capable of being charged and discharged, is installed as an auxiliary power source for supplying power to drive a motor in addition to a fuel cell, which is a main power source, not only in small vehicles but also in large vehicles such as buses and the like. This hybrid fuel-cell vehicle may improve the efficiency of the system. However, since the fuel cell and the high-voltage battery are used at the same time as described above, the insulation resistance may decrease to less than a certain level, entailing the risk of a driver receiving an electrical shock.
The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.